The flaw could be potentially exploited by threat actors to carry out phishing attacks and other malicious activities.
According to an analysis conducted by LiveOverflow, the XSS vulnerability was apparently introduced on September 26, 2018, when a sanitization mechanism was removed after the review of the user interface design.
The design change was reverted on February 22, 2019, Google confirmed to have quickly addressed the vulnerability shortly after learning of its existence.
The analysis of the comments posted by developers when the change was reverted revealed that the bug was related to an HTML sanitizer. The issue was the root cause of the introduction of an XSS flaw in the Google Web Server (GWS) software.
Experts at LiveOverflow speculated the vulnerability likely affected other Google products that use the Closure library.
LiveOverflow has published a video PoC for the vulnerability:
Pierluigi Paganini is member of the ENISA (European Union Agency for Network and Information Security) Threat Landscape Stakeholder Group and Cyber G7 Group, he is also a Security Evangelist, Security Analyst and Freelance Writer.
Editor-in-Chief at "Cyber Defense Magazine", Pierluigi is a cyber security expert with over 20 years experience in the field, he is Certified Ethical Hacker at EC Council in London. The passion for writing and a strong belief that security is founded on sharing and awareness led Pierluigi to find the security blog "Security Affairs" recently named a Top National Security Resource for US.
Pierluigi is a member of the "The Hacker News" team and he is a writer for some major publications in the field such as Cyber War Zone, ICTTF, Infosec Island, Infosec Institute, The Hacker News Magazine and for many other Security magazines.
Author of the Books "The Deep Dark Web" and “Digital Virtual Currency and Bitcoin”.